We made use of the Bar-Code app for iPhone since it can email the lists of bar codes you scan. This made it easy to go through our books and dvds once, and not have to type anything in ourselves.

Results

It then provides a summary of which items are eligible, and if so, how much Amazon will give you. For example, with the number of books we have around the house that we're trying to slowly get rid of, we organize our books: